Malicious PDF — malware analysis report

Static analysis result for SHA-256 7242d96ba08ff32f…

MALICIOUS

PDF

68.1 KB Created: 2021-04-23 22:00:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 7b42ea16ce642b1b47b378f66adc039b SHA-1: 81b26bb1a3eee5124c5a1b52b0e6984c6eb2bebd SHA-256: 7242d96ba08ff32f6510246df29562655c05fcf438a1f0a3b90578a639b1f286
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by a machine learning classifier and ClamAV as malicious. Heuristics indicate it functions as a link farm with numerous external URIs, suggesting a phishing or malware distribution attempt. The document body, though heavily obfuscated, contains metadata related to 'business communication articles' and the wkhtmltopdf tool, which could be part of a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://vectorcorp.net/sites/default/files/webform/resume/30106672217.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/71048230710.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/nozixedexifanozavarojiro.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/wibojamivumararevede.pdfIn PDF document text
    • https://www.cdcplumbing.com/sites/default/files/webform/contact-us/65589142167.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/bujepalifomi.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/85138354947.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/52844377902.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/tuwagamutavuvefofufeniz.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/taxebuvokorutupimapo.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/mogewewe.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/tevesifisota.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=business+communication+articlesPDF link annotation
    • https://umatter.princeton.edu/system/files/webform/requests/72435273025.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/sutuzosugogaw.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD014 4996 bytes
SHA-256: 488327666eafe6572abe7e447fc15969725c3c23447a3aa12f1c34b091b796dc
font_01_sfnt_off0000e0f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0F5 10084 bytes
SHA-256: bff53379b723ce5b21bf82dc48156c1d47114b47fbc48fa67df70ec520e69146